Abstract
There has been ample debate on whether cell membranes can present macroscopic lipid domains as predicted by three-component phase diagrams obtained by fluorescence microscopy. Several groups have argued that membrane proteins and interactions with the cytoskeleton inhibit the formation of large domains. In contrast, some polarizable cells do show large regions with qualitative differences in lipid fluidity. It is important to ask more precisely, based on the current phase diagrams, under what conditions would large domains be expected to form in cells. In this work we study the thermotropic phase behavior of the platelet plasma membrane by FTIR, and compare it to a POPC/Sphingomyelin/Cholesterol model representing the outer leaflet composition. We find that this model closely reflects the platelet phase behavior. Previous work has shown that the platelet plasma membrane presents inhomogeneous distribution of DiI18:0 at 24 °C, but not at 37 °C, which suggests the formation of macroscopic lipid domains at low temperatures. We show by fluorescence microscopy, and by comparison with published phase diagrams, that the outer leaflet model system enters the macroscopic domain region only at the lower temperature. In addition, the low cholesterol content in platelets (∼ 15 mol%), appears to be crucial for the formation of large domains during cooling.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1229-1237 |
| Number of pages | 9 |
| Journal | Biochimica et Biophysica Acta - Biomembranes |
| Volume | 1788 |
| Issue number | 6 |
| DOIs | |
| State | Published - Jun 2009 |
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Keywords
- Cholesterol
- FTIR
- Lipid domain formation
- Lipid membrane thermodynamics
- Lipid platform
- Lipid raft
- Liquid-ordered phase
- Platelet
ASJC Scopus subject areas
- Biochemistry
- Cell Biology
- Biophysics
Cite this
Macroscopic domain formation during cooling in the platelet plasma membrane : An issue of low cholesterol content. / Bali, Rachna; Savino, Laura; Ramirez, Diego A.; Tsvetkova, Nelly M.; Bagatolli, Luis; Tablin, Fern; Crowe, John H.; Leidy, Chad.
In: Biochimica et Biophysica Acta - Biomembranes, Vol. 1788, No. 6, 06.2009, p. 1229-1237.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Macroscopic domain formation during cooling in the platelet plasma membrane
T2 - An issue of low cholesterol content
AU - Bali, Rachna
AU - Savino, Laura
AU - Ramirez, Diego A.
AU - Tsvetkova, Nelly M.
AU - Bagatolli, Luis
AU - Tablin, Fern
AU - Crowe, John H.
AU - Leidy, Chad
PY - 2009/6
Y1 - 2009/6
N2 - There has been ample debate on whether cell membranes can present macroscopic lipid domains as predicted by three-component phase diagrams obtained by fluorescence microscopy. Several groups have argued that membrane proteins and interactions with the cytoskeleton inhibit the formation of large domains. In contrast, some polarizable cells do show large regions with qualitative differences in lipid fluidity. It is important to ask more precisely, based on the current phase diagrams, under what conditions would large domains be expected to form in cells. In this work we study the thermotropic phase behavior of the platelet plasma membrane by FTIR, and compare it to a POPC/Sphingomyelin/Cholesterol model representing the outer leaflet composition. We find that this model closely reflects the platelet phase behavior. Previous work has shown that the platelet plasma membrane presents inhomogeneous distribution of DiI18:0 at 24 °C, but not at 37 °C, which suggests the formation of macroscopic lipid domains at low temperatures. We show by fluorescence microscopy, and by comparison with published phase diagrams, that the outer leaflet model system enters the macroscopic domain region only at the lower temperature. In addition, the low cholesterol content in platelets (∼ 15 mol%), appears to be crucial for the formation of large domains during cooling.
AB - There has been ample debate on whether cell membranes can present macroscopic lipid domains as predicted by three-component phase diagrams obtained by fluorescence microscopy. Several groups have argued that membrane proteins and interactions with the cytoskeleton inhibit the formation of large domains. In contrast, some polarizable cells do show large regions with qualitative differences in lipid fluidity. It is important to ask more precisely, based on the current phase diagrams, under what conditions would large domains be expected to form in cells. In this work we study the thermotropic phase behavior of the platelet plasma membrane by FTIR, and compare it to a POPC/Sphingomyelin/Cholesterol model representing the outer leaflet composition. We find that this model closely reflects the platelet phase behavior. Previous work has shown that the platelet plasma membrane presents inhomogeneous distribution of DiI18:0 at 24 °C, but not at 37 °C, which suggests the formation of macroscopic lipid domains at low temperatures. We show by fluorescence microscopy, and by comparison with published phase diagrams, that the outer leaflet model system enters the macroscopic domain region only at the lower temperature. In addition, the low cholesterol content in platelets (∼ 15 mol%), appears to be crucial for the formation of large domains during cooling.
KW - Cholesterol
KW - FTIR
KW - Lipid domain formation
KW - Lipid membrane thermodynamics
KW - Lipid platform
KW - Lipid raft
KW - Liquid-ordered phase
KW - Platelet
UR - http://www.scopus.com/inward/record.url?scp=65549150325&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=65549150325&partnerID=8YFLogxK
U2 - 10.1016/j.bbamem.2009.03.017
DO - 10.1016/j.bbamem.2009.03.017
M3 - Article
C2 - 19341703
AN - SCOPUS:65549150325
VL - 1788
SP - 1229
EP - 1237
JO - Biochimica et Biophysica Acta - Biomembranes
JF - Biochimica et Biophysica Acta - Biomembranes
SN - 0005-2736
IS - 6
ER -